Circuit board



FIG. 1 is a perspective view of a circuit board showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken lines shown in the drawings illustrate unclaimed portions and form no part of the claimed design.

All surfaces not shown form no part of the claimed design. 

CLAIM The ornamental design for a circuit board, as shown and described. 